Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.


  1. Advanced Patent Search
Publication numberUS5061242 A
Publication typeGrant
Application numberUS 07/381,350
Publication dateOct 29, 1991
Filing dateJul 18, 1989
Priority dateJul 18, 1989
Fee statusPaid
Also published asCA2021284A1, CA2021284C, DE69007194D1, DE69007194T2, EP0409511A1, EP0409511B1
Publication number07381350, 381350, US 5061242 A, US 5061242A, US-A-5061242, US5061242 A, US5061242A
InventorsEdward J. Sampson
Original AssigneeInfusaid, Inc.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Adjustable implantable drug infusion system
US 5061242 A
A drug delivery system for implantation into a living body having a pressure actuated infusion pump and an adjustable flow regulator. The regulator comprises a body having a regulator cavity divided by a diaphragm into two chambers. One chamber serves as a pressure sensor and the other as a conduit through which fluid flows. The outlet from the conduit chamber can be sealed by diaphragm movement as a function of pressure increase or the flow restricted. The outlet itself is mounted on an adjustable fitting that is movable relative to the diaphragm. The distance between the outlet and the diaphragm may be set as a calibration of the regulator.
Previous page
Next page
Having defined my invention, I claim:
1. A drug delivery system for implantation in a living body comprising:
a pressure actuated drug delivery device having a housing, a movable member dividing said housing into two compartments, a first compartment containing a drug to be dispensed and a second compartment containing a material exerting pressure on said movable member, means for providing access to said first compartment for refilling it with a drug;
an adjustable pressure sensitive flow regulator connected to said first compartment, said flow regulator comprising a body, an inlet from said first compartment and an outlet to a catheter said outlet mounted in said body and movable thereto, a cavity divided by a flexible sensing member to define two chambers, one chamber on each side of said flexible sensing member, means to establish fluid communication between said two chambers, one of said chambers in fluid communication with said outlet, said means to move said outlet with respect to said flexible sensing member for adjusting the flow rate to said outlet from said other of said chambers such that said regulator flow is variably adjustable to any predetermined rate.
2. The drug delivery system of claim 1 further comprising a first movable fitting having a flange, said outlet comprising a stem fitted to said first movable fitting, a second movable fitting loosely coupled to said first movable fitting and tightly attached to said body allowing movement substantially perpendicular said flexible sensing member, said second movable fitting housing an O-ring seated to contact said flexible sensing member and close off said outlet when said means to move has been adjusted, and said means to move comprising an adjusting nut mounted in said body and contacting said flange on said first movable fitting, whereby movement of said nut positions said first and second movable fittings and said O-ring relative to said flexible sensing member.
3. The drug delivery system of claim 1, wherein said flexible sensing member is a metallic diaphragm mounted in said body, said metallic diaphragm movable in response to a pressure differential between said first and said second chambers.
4. The drug delivery system of claim 2 further comprising an adjustable sealing diaphragm mounted to said second movable fitting and to said body, said adjustable sealing diaphragm movable in response to movement of said adjusting nut to maintain a seal in said first cavity.
5. The drug delivery system of claim 1, wherein said regulator body comprises a pair of body components, one of said components having said inlet and a hollow portion defining one of said chambers, the other of said components having said outlet and said means to establish fluid communication contained therein, and means to join said pair of body components together in a sealed manner.
6. The drug delivery system of claim 5, wherein the other of said components comprises a depending flange, said flexible member being mounted on said flange.

1. Field of the Invention

This invention is directed to a system for accurately controlling the flow rate of a drug from an implantable drug delivery device. One device of this type is the implantable infusion pump described in U.S. Pat. No. 3,731,681. This invention is an improvement over the system disclosed in U.S. Pat. No. 4,299,220 which relates to a compensating mechanism for an implantable pump. These devices are used to deliver drugs at a very slow rate over a long period of time prior to subcutaneous refill.

2 . Prior Art

U.S. Pat. No. 3,731,681 describes an implantable infusion pump which utilizes the vapor pressure of a two stage gas to maintain a constant pressure on a drug flowing through a capillary tube in order to maintain a constant flow rate. This technique of flow control while simple and reliable is sensitive to outside variables such as body temperature and atmospheric pressure. Because the temperature of the body in which the device is implanted remains relatively constant, the vapor pressure also stays constant. Thus, while the patient remains at one local ground level air pressure is also essentially constant. However, there are conditions in which both temperature and atmospheric pressure may significantly change. If, for example, the patient has a high fever and at the same time takes a ride in an airplane where the atmosphere pressure is much lower than at sea level the high vapor pressure inside the pump due to the fever and the low pressure outside the pump due to the high altitude will cause pump to flow at a rate about 25% higher than at standard temperature and at sea level. While the drug dosage can be adjusted by changing the concentration of drug in the pump this, never the less, is a serious inconvenience and hardship for the patient.

U.S. Pat. No. 4,299,220 defines an improved implantable pump system employing a regulator to compensate for variations in pressure and temperature and thereby insure a more accurate and uniform rate of drug delivery. The implantable flow regulator of the '220 patent employs a body having a shallow internal cavity and a flexible diaphragm in the body which divides the cavity into two chambers. An inlet is provided to each of the chambers. An outlet is provided leading from the second of the chambers and is centrally disposed in the wall of the cavity underlying the diaphragm. Thus, flexing of the diaphragm in one direction contacts an elastomeric sealing ring around the outlet and closes the fluid passage way. The inlet of the regulator body is adapted to be connected to the capillary flow line from a pressure actuated drug delivery device. The flow line includes at least one capillary restrictor upstream from the inlet to the second chamber. The outlet from the second chamber of the regulator body is adapted to be connected to a catheter flow line extending to the desired infusion cite within the patient.

The capillary restrictor is thus in series with the flow control valve which is formed by the outlet and the diaphragm. The normal pressure drop across the capillary is less than the minimum pressure drop across the entire system, that is the pressure difference between the drug chamber and the distal end of the catheter in the outside environment of the infusion site. The pressure drop across the capillary tube is sensed by the diaphragm. When the opposing forces on the diaphragm are stable, the diaphragm is stationary. If there is a change in these forces, the diaphragm deflects either to close the valve when the pressure difference is negative in the second chamber or to open the valve if the pressure difference is positive in the second chamber.


This invention is directed to an improvement over the system disclosed in the '220 patent. One of the difficulties in that system is not being able to adjust the position of the diaphragm in relation to the valve. Consequently, the device, generally a fixed assembly, provides a widely varying initial flow rate due to manufacturing tolerances and is impossible to normalize. It would be desirable to be able to null the sensing diaphragm in test and to adjust the valve fitting for a normalized flow condition. However, in prior systems there is no way to change the initial manufactured set up of the device. Clearly, the ability to calibrate or adjust the device could insure that in-vivo performance will be as close as possible to design specifications and patient requirements.

Thus, in accordance with this invention a flexible diaphragm is incorporated in the valve design to allow for set-up and calibration adjustments to the system flow rate.

This invention will be described in greater detail by reference to the accompanying drawing and description of the preferred embodiment that follows.


FIG. 1 is a schematic representation of the flow regulator according to this invention when used in conjunction with a pressure actuated drug delivery system: and

FIG. 2 is a section view of a flow rate regulator as illustrated in FIG. 1.

The implantable drug delivery system is illustrated schematically in FIG. 1. It comprises an infusion pump 10 with a housing 12 divided into a drug chamber 16 and a propellant chamber 18 by means of a bellows or diaphragm 20. The infusion pump is implanted under the skin and the drug chamber may be refilled hypodermically utilizing a penetrable resilient fill septum 24. The chamber 18 contains Freon having a vapor pressure such that, under conditions of normal body temperature, creates a pressure upon the bellows 20 to force a drug contained in the chamber 16 out through the discharge opening 26, through a filter 30, to the flow rate compensator 28. In this schematic the compensator incorporates a capillary type restrictor 38.

Referring to FIG. 2, the flow rate compensator in accordance with this invention comprises a body 28 having a top member 40 and a bottom member 42. The top portion of the bottom body member 42 and the bottom portion of the top body member 40 have flush mating surfaces at their peripheries. The resilient sensing diaphragm 44 is composed of a flexible but impervious material, such as titanium and is disposed in a cavity which the diaphragm divides into two chambers 46 and 48. The diaphragm is welded to a radial flange 41 on the top body member 40.

The top member 40 and the bottom member 42 are assembled and fastened together by any convenient means such as screws, not illustrated, welding or the like. The space in the bottom surface of the top member 48 along with the space 46 in the top of bottom body portion following assembly forms a chamber divided by the diaphragm 44.

The bottom body member 42 has an inlet passage 50 communicating with chamber 46. An outlet passage 52 connects to the flow line and to the sideport 32. As illustrated in FIG. 1, this sideport is a "T" connection into the system via passage 36. Alternatively, the outlet 52 may be in series with the sideport 32 on an in-line basis to the catheter 34.

In accordance with this invention, the inlet 50 is threaded directly onto the pump. A seal not illustrated, is placed around inlet, 50 to seal this coupling. Fluid from the drug chamber 16 flows through inlet 50 into the lower chamber 46. Via conduit 51, fluid from the lower chamber 46 is fed to an passage 54 in the upper member 40. This element provides an outlet to one side of the restrictor 38. At an opposite position on the upper member 40, a second passage 56 is disposed receiving fluid from the restrictor 38 and providing a conduit 53 to the upper chamber 48.

By this technique then, fluid is delivered unrestricted to chamber 46 and then through the restrictor 38 to chamber 48. Thus, the restrictor 38 communicates directly across the sensing diaphragm .

The outlet 52 is welded to a first portion 58 of an adjustable fitting. An O-ring 59 provides a seal in a recess of portion 58. A second portion of the adjustable fitting comprises a plate 60 having an O-ring valve 62 positioned in the recess at the lower portion thereof. A flexible diaphragm 64 is welded at its periphery in a narrow recess in the upper housing 40 and to the plate 60 comprising the second portion of the adjustable fitting. As can be appreciated then, movement of the fitting 58, 60 produces deflection in the adjustable fitting diaphragm 64.

Adjustment is by means of an internal Castle nut 66. By rotation of the castle nut 66, which bears on a flange 68 of the upper adjustable portion 58, a downward pressure is exerted causing the adjustable fitting and the adjustable fitting diaphragm 64 to be urged in a direction towards the sensing diaphragm 44. When the O-ring valve 62 contacts the titanium sensing diaphragm 44 the outlet 52 is thereby effectively sealed off. Adjustment from that sealed position is a function of movement of the Castle nut 66 so that a clearance exists between the O-ring valve 62 and the surface of the sensing diaphragm 44. By this technique, effective attenuation of the flow through 62 from chamber 48 to outlet 52 can be established and maintained automatically by the varying forces on the sensing diaphragm 44 due to changes in body temperature and atmospheric pressure.

This technique also provides for adjustment during manufacture to insure that the device is properly calibrated. Without such adjustment, the operation of the device would be a function of manufacturing tolerances which provide an inadequate basis by which to insure a predetermined regulated flow given the low volume flow rates.

In operation, medication from the drug chamber 16 is forced through the flow line 26 by the constant pressure exerted by the material in the chamber 18. The medication passing through the filter 30 is then delivered to the compensator through inlet 50. Medication flows into lower chamber 46 and via opening 54 into the restrictor 38. Then, it is delivered to the upper chamber 48 and through the outlet 52 into the catheter 34. Given the fact that there is fluid in both chambers 46 and 48, opposing forces on the diaphragm generally null the system so that the diaphragm tends to remain stationery.

If, however, there is a change in these forces, for example, as a result of a decrease in flow through the catheter 34 because of a higher atmospheric pressure, then the diaphragm 44 will be deflected downward, due to a build up of pressure in chamber 48 automatically opening O-ring valve 62 increasing flow. If, on the other hand, the pressure in chamber 48 is reduced by a lowering of atmospheric pressure such as at a higher altitude, the diaphragm will be deflected upward toward O-ring valve 62 automatically closing O-ring valve 62 reducing flow. Thus, the position of the diaphragm, which is controlled by the pressure differential between chambers 46 and 48, effectively maintains a constant or near constant flow rate through outlet 52 to catheter 34.

Given the fact that movement of the diaphragm 44 to establish a flow rate from a fully seated no flow rate condition to the desired dosage level is very small, as discussed herein adjustability of the system is required. Thus, by using the Castle nut 66 and the adjustable diaphragm feature of 60 the initial distance between the O-ring valve 62 and the diaphragm 44 can be adjusted and set to give proper flow rate. This is a material improvement over prior art systems which do not allow for such adjustability.

It is apparent that modifications and variations of this invention may be made without departing from the essential scope thereof.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US4221219 *Jul 31, 1978Sep 9, 1980Metal Bellows CorporationImplantable infusion apparatus and method
US4299220 *May 3, 1979Nov 10, 1981The Regents Of The University Of MinnesotaImplantable drug infusion regulator
US4447224 *Sep 20, 1982May 8, 1984Infusaid CorporationVariable flow implantable infusion apparatus
US4486190 *Dec 27, 1982Dec 4, 1984Consolidated Controls CorporationPrecision medication dispensing system and method
US4515588 *May 16, 1983May 7, 1985Health Care Concepts, Inc.I.V. flow regulator
US4838887 *Dec 15, 1987Jun 13, 1989Shiley Infusaid Inc.Programmable valve pump
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US5197322 *Nov 29, 1990Mar 30, 1993Minimed Technologies, Ltd.Pressure reservoir filling process for an implantable medication infusion pump
US5207645 *Jun 25, 1991May 4, 1993Medication Delivery DevicesInfusion pump, treatment fluid bag therefor, and method for the use thereof
US5308335 *Nov 2, 1992May 3, 1994Medication Delivery DevicesInfusion pump, treatment fluid bag therefor, and method for the use thereof
US5328465 *Oct 30, 1992Jul 12, 1994Medtronic, Inc.Apparatus and method for limiting access to septum
US5352201 *Feb 3, 1994Oct 4, 1994Block Medical, Inc.Compact uniform pressure infusion apparatus
US5395320 *Nov 9, 1993Mar 7, 1995Sabratek CorporationProgrammable infusion pump with interchangeable tubing
US5433704 *May 3, 1994Jul 18, 1995Medication Delivery DevicesInfusion pump, treatment fluid bag therefor, and method for the use thereof
US5443450 *Apr 29, 1994Aug 22, 1995Medtronic, Inc.Medication delivery device and method of construction
US5445616 *Apr 29, 1994Aug 29, 1995Medtronic, Inc.Medication delivery device and method of construction
US5527307 *Apr 1, 1994Jun 18, 1996Minimed Inc.Implantable medication infusion pump with discharge side port
US5551849 *Apr 29, 1994Sep 3, 1996Medtronic, Inc.Medication delivery device and method of construction
US5609575 *Apr 4, 1995Mar 11, 1997Graseby Medical LimitedInfusion pump and method with dose-rate calculation
US5620312 *Mar 6, 1995Apr 15, 1997Sabratek CorporationInfusion pump with dual-latching mechanism
US5628619 *Mar 6, 1995May 13, 1997Sabratek CorporationInfusion pump having power-saving modes
US5637093 *Mar 6, 1995Jun 10, 1997Sabratek CorporationInfusion pump with selective backlight
US5645540 *Oct 11, 1994Jul 8, 1997Stryker CorporationBlood conservation system
US5766155 *Mar 11, 1997Jun 16, 1998Sabratek CorporationInfusion pump with selective backlight
US5785681 *Feb 25, 1997Jul 28, 1998Minimed Inc.Flow rate controller for a medication infusion pump
US5791880 *Feb 18, 1997Aug 11, 1998Sabratek CorporationInfusion pump having power-saving modes
US5795327 *Mar 6, 1995Aug 18, 1998Sabratek CorporationInfusion pump with historical data recording
US5820589 *Apr 30, 1996Oct 13, 1998Medtronic, Inc.Implantable non-invasive rate-adjustable pump
US5830198 *Apr 25, 1997Nov 3, 1998Stryker CorporationBlood conservation system
US5904668 *Mar 6, 1995May 18, 1999Sabratek CorporationCassette for an infusion pump
US5993420 *Jan 22, 1998Nov 30, 1999Sabratek CorporationCassette for an infusion pump
US6099495 *Apr 30, 1998Aug 8, 2000Medtronic, Inc.Implantable electrical transducer powered from capacitive storage energy source
US6283949Dec 27, 1999Sep 4, 2001Advanced Cardiovascular Systems, Inc.Refillable implantable drug delivery pump
US6468242Jun 5, 1998Oct 22, 2002Baxter International Inc.Medical apparatus with patient data recording
US6764472Jan 11, 2000Jul 20, 2004Bard Access Systems, Inc.Implantable refillable infusion device
US6932796May 15, 2002Aug 23, 2005Tearafuse, Inc.Liquid metering system
US6960184Jun 18, 2002Nov 1, 2005Biovalve Technologies, Inc.Injection devices
US7022107Sep 27, 2000Apr 4, 2006Advanced Infusion, Inc.Infusion pump with pressure regulator
US7108686Jan 11, 2001Sep 19, 2006Bard Access Systems, Inc.Implantable, refillable infusion device and septum replacement kit
US7150409Nov 30, 2001Dec 19, 2006Biovalve Technologies, Inc.Injection systems
US7268859Feb 6, 2004Sep 11, 2007Therafuse, Inc.Liquid measuring system
US7341577Apr 30, 2003Mar 11, 2008Renishaw PlcImplantable drug delivery pump
US7361155Sep 16, 2003Apr 22, 2008Therafuse, Inc.Compensating liquid delivery system and method
US7510552Aug 12, 2005Mar 31, 2009Infusion Systems, LlcImplantable medication delivery device using pressure regulator
US7563255May 2, 2002Jul 21, 2009Massachusetts Eye And Ear InfirmaryImplantable drug delivery device and use thereof
US7637892Nov 17, 2006Dec 29, 2009Palyon Medical (Bvi) LimitedVariable flow infusion pump system
US7740607Feb 22, 2005Jun 22, 2010Valeritas, Inc.Modular units for use in an injection device
US7776029Jan 24, 2002Aug 17, 2010The Alfred E. Mann Foundation For Scientific ResearchMicrominiature infusion pump
US7806867Sep 8, 2003Oct 5, 2010Valeritas, Inc.Injection device
US8038650Feb 22, 2010Oct 18, 2011Microsert Ltd.Slow release liquid drug delivery device
US8114055May 10, 2005Feb 14, 2012Palyon Medical (Bvi) LimitedImplantable pump with infinitely variable resistor
US8177750Nov 19, 2009May 15, 2012Palyon Medical (Bvi) LimitedVariable flow infusion pump system
US8211060May 10, 2005Jul 3, 2012Palyon Medical (Bvi) LimitedReduced size implantable pump
US8337488Sep 22, 2009Dec 25, 2012Incube Labs, LlcDiaphragm drug pump
US8500681Mar 21, 2011Aug 6, 2013Valeritas, Inc.Injection systems
US8568360Dec 28, 2011Oct 29, 2013Palyon Medical (Bvi) LimitedProgrammable implantable pump design
US8591478Jun 7, 2012Nov 26, 2013Palyon Medical (Bvi) LimitedReduced size implantable pump
US8668675Nov 3, 2011Mar 11, 2014Flugen, Inc.Wearable drug delivery device having spring drive and sliding actuation mechanism
US8858787Oct 22, 2007Oct 14, 2014Baxter International Inc.Dialysis system having non-invasive fluid velocity sensing
US8915893Dec 28, 2011Dec 23, 2014Palyon Medical (Bvi) LimitedVariable flow infusion pump system
US8961466Oct 16, 2013Feb 24, 2015Palyon Medical (Bvi) LimitedProgrammable implantable pump design
US8992503Mar 27, 2012Mar 31, 2015Microsert Ltd.Miniature implanted drug delivery devices and inserter systems for introducing such devices
US9238102Sep 10, 2010Jan 19, 2016Medipacs, Inc.Low profile actuator and improved method of caregiver controlled administration of therapeutics
US9500186Jan 31, 2011Nov 22, 2016Medipacs, Inc.High surface area polymer actuator with gas mitigating components
US9724456Oct 8, 2014Aug 8, 2017Baxter International Inc.Dialysis system having non-invasive fluid velocity sensing
US20020004639 *Jan 5, 2001Jan 10, 2002Willis John P.Injection device
US20020151842 *Nov 30, 2001Oct 17, 2002Gonnelli Robert R.Injection systems
US20020156418 *Nov 30, 2001Oct 24, 2002Gonnelli Robert R.Injection systems
US20020161329 *Nov 30, 2001Oct 31, 2002Gonnelli Robert R.Injection systems
US20030149397 *Nov 30, 2001Aug 7, 2003Gonnelli Robert R.Injection systems
US20030176797 *Mar 12, 2002Sep 18, 2003Fernando AnzelliniThrombust; implantable delivery system sensible to self diagnosis of acute myocardial infarction for thrombolysis in the first minutes of chest pain
US20030221418 *Jan 28, 2003Dec 4, 2003Gopichandra SurnillaMethod for rapid catalyst heating
US20040082908 *Jan 24, 2002Apr 29, 2004Whitehurst Todd K.Microminiature infusion pump
US20040220525 *Sep 8, 2003Nov 4, 2004Willis John PInjection device
US20040249339 *Jun 18, 2002Dec 9, 2004Biovalve Technologies, Inc.Injection devices
US20040249363 *Jun 17, 2004Dec 9, 2004Bard Access Systems, Inc.Implantable, refillable infusion device and septum replacement kit
US20050005710 *Feb 26, 2004Jan 13, 2005Therafuse, Inc.Liquid metering system
US20050050941 *Feb 6, 2004Mar 10, 2005Sage Burton H.Liquid measuring system
US20050059926 *Sep 16, 2003Mar 17, 2005Therafuse, Inc.Compensating liquid delivery system and method
US20050154350 *Feb 22, 2005Jul 14, 2005Biovalve Technologies, Inc.Injection devices
US20050273083 *Aug 12, 2005Dec 8, 2005Lebel Ronald JImplantable medication delivery device using pressure regulator
US20060259015 *May 10, 2005Nov 16, 2006Palion Medical CorporationImplantable pump with infinitely variable resistor
US20060259016 *May 10, 2005Nov 16, 2006Palion Medical CorporationReduced size implantable pump
US20060276744 *May 22, 2006Dec 7, 2006Falk Theodore JConfiguration for drug delivery systems
US20070005044 *Jun 21, 2005Jan 4, 2007Palion Medical CorporationImplantable pump with infinitely variable resistor
US20070112328 *Nov 17, 2006May 17, 2007Palyon Medical CorporationVariable flow infusion pump system
US20070129678 *Dec 6, 2005Jun 7, 2007Medtronic, Inc.Regulator
US20080015494 *Jul 11, 2007Jan 17, 2008Microchips, Inc.Multi-reservoir pump device for dialysis, biosensing, or delivery of substances
US20090101550 *Oct 22, 2007Apr 23, 2009Baxter International Inc.Dialysis system having non-invasive fluid velocity sensing
US20090270844 *Apr 24, 2008Oct 29, 2009Medtronic, Inc.Flow sensor controlled infusion device
US20100069892 *Nov 19, 2009Mar 18, 2010Palyon Medical (Bvi) LimitedVariable flow infusion pump system
US20100076413 *Sep 22, 2009Mar 25, 2010Mir ImranDiaphragm drug pump
US20110172634 *Mar 21, 2011Jul 14, 2011Valeritas, Inc.Injection systems
US20110208122 *Feb 22, 2010Aug 25, 2011Avraham ShekalimSlow release liquid drug delivery device
USRE35501 *Dec 19, 1994May 6, 1997Medication Delivery DevicesInfusion pump, treatment fluid bag therefor, and method for the use thereof
WO1994009847A1 *Nov 2, 1992May 11, 1994Medication Delivery DevicesInfusion pump, bag and method of use
WO2001012158A1 *Aug 16, 2000Feb 22, 2001Thomas Jefferson UniversityImplantable drug delivery catheter system with capillary interface
WO2001097695A1Jun 20, 2000Dec 27, 2001Chf Solutions, Inc.Anastomosis device and method
U.S. Classification604/118, 604/141, 604/246
International ClassificationA61M5/142, A61M31/00, A61M37/00, G05D7/01, A61M5/168
Cooperative ClassificationA61M2005/14264, A61M5/14276, G05D7/0113, A61M5/16881
European ClassificationA61M5/168F1, G05D7/01B4
Legal Events
Jul 18, 1989ASAssignment
Effective date: 19890710
Mar 13, 1995FPAYFee payment
Year of fee payment: 4
Mar 13, 1996ASAssignment
Free format text: MERGER;ASSIGNOR:INFUSAID, INC.;REEL/FRAME:007846/0197
Effective date: 19950125
Jan 12, 1999ASAssignment
Effective date: 19970715
Mar 26, 1999FPAYFee payment
Year of fee payment: 8
Apr 14, 2003FPAYFee payment
Year of fee payment: 12
May 14, 2003REMIMaintenance fee reminder mailed